Merge pull request #1033 from meolu/dependabot/pip/requirements/werkzeug-0.15.3

Bump werkzeug from 0.14 to 0.15.3 in /requirements

requirements/prod.txt

@@ -7,7 +7,7 @@ gevent-websocket==0.10.1
 # Flask
 Flask==1.0.2
 MarkupSafe==1.0
-Werkzeug==0.14
+Werkzeug==0.15.3
 Jinja2==2.10
 Flask-RESTful==0.3.5
 Flask-Babel==0.11.2